Berlin is one of the most water-rich cities in Germany. But climate change does not stop at the Havel, Spree or Wannsee either. Dr. Michael Hupfer is working at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB). In one of his current research projects at the IGB, the hydrobiologist is investigating the effects of climate change on urban lakes. In an interview, he tells us more about water warming, heavy rainfall, blue-green algae and fish mortality. And he explains what we can do on a small scale to relieve our water bodies.